Abrasive wheel



July 19, 1938. E. VAN DER PYL.

AlRAsIvE WHEEL Filed Oct. 9,. 1936 lf-K..

Patented July 19, 1938 UNITED STATES vPATENT OFFICE ABRASIVE WHEEL Application October 9,`

Claims.

l object of the invention is to provide an inexpensive and satisfactory bond for abrasive bodies. Another object of the invention is to provide an eflicient cold setting bond. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements y and arrangements of parts, and in the several steps and relation and order of each of said steps to one or more ofthe others thereof, all as will be Illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing illustrating one of many possible embodiments of the mechanical features of this invention,

Figure 1 is a plan view of a .mounting plate and wire reinforcement upon which the abrasive disk may be formed,

Figure 2 is an enlarged fragmentary cross sectional view, taken on the line 2`2 of Figure 1, Figure 3 is a perspective view of a nut,-

Figure 4 is a sectional view of a mold illustrating a preferred manner of manufacturing the abrasive article,

Figure 5 is a fragmentary sectional view of part of the mold after the pressing operation,

Figure 6 lis a side elevation of the completed disk and mounting. f

Referring first to Figures 1 and 4, I provide a mounting or backing plate in the form of a steel disk III having a central axial hole Il, a plurality of countersunk holes I2 close to the hole II, and a plurality of additional countersunk holes I3 i` distributed over the plate I0. Referring now to Figure 2, in each hole I3 is located a screw I I. I provide, as shown in Figures 1, 2, and 4, a steel wire mesh I5 cut to annular shape. I place the wire mesh Ii'upon the plate I0 with the screws I4 projecting through openings. I then fasten the parts together by means of nuts I6, the nutsy being formed so that they will interlock with the meshes as clearly shown.

The foregoing constitutes a backing plate to which is firmly united the screen mesh I5. I now 1936, Serial No. 104,860

mold a grinding disk in situ upon the backing plate and around the screen mesh in the following manner.

I provide abrasive grain ofany desired abrasive material, for example fused alumina or silicon 5 carbide,l emery or corundum, or diamonds. I prefer to use fused alumina and silicon carbide.

I provide a quantity of cast iron in finely divided form, for example iron lings which will pass through a 3() mesh screen or finer. I provide a 10 quantity of sal ammoniac. The proportions of the ingredients may be widely varied but for pur- .v poses of illustration satisfactory results may be achieved using 40 parts of abrasive grain, 40 parts of iron filings, and two to ten parts of sal l5 ammoniac, all by weight. I mix these ingredients thoroughly in any suitable manner and add enough water to wet the mixture thoroughly.

Referring now to Figure 4, I mount the plate Ill upon the bottom plate 20 of a mold. An an- 20 nular mold ring 2| of a diameter the same as thev diameter of the plate Ill is now placed around the plate III, as shown in Figure 4, suitable spacers 22 being used if desired. I next place upon the plate III a central plug core 23 having a central 25 pin 2l which fits in the hole II.

I now fill the space between the core 23 and the ring 2| with the desired Vquantity of the mixture made as hereinbefore specified. I then place a top plate 25 upon the abrasive mixture. The 30 entire mold is then pressed between the platten 26 and the top plate 21 of a suitable press. I may press to definite volumetric limits and the press- Ving is preferably of the order of several thousand pounds to the square inch in order thoroughly to 35 compact the mass.

Sal ammoniac, otherwise known as ammonium chloride (NH4C1) together with water and iron forms a solution at room temperatures in which some of the iron becomes FeClz and some of it 40 precipitates as iron hydroxide. The iron chloride is a satisfactory bond even though mixed with some iron hydroxide and a satisfactory reaction takes place during and after a cold pressing operation.' The bond sets complete in a few hours 45 after the wheel is pressed.

The bond is relatively soft and therefore a grinding disk of free cutting characteristics is produced. I may use diamonds as the abrasive and form a wheel or an annulus thereof with or 50 without the special structural features described and illustrated. Diamonds bonded with the bond herein described are found to be effective for the grinding of tungsten carbide and similar mate- It will thus be seen that there has been pro vided by this invention an article and a method in which the various objects hereinbefore set' forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiments might be made of the mechanical features of the above invention and 2. An abrasive article comprising abrasive grain and a bond which is the reaction product of iron lings and sal ammoniac.

3. An abrasive product comprising abrasive grains yand a bond resulting from the reaction of iron with a halide of ammonia.

4. The method of making an abrasive article which consists in providing a quantity of abrasive grain, mixing the abrasive grain with comminuted iron, a halide of ammonia. and water, pressing and allowing to set cold.

5. An abrasive article comprising abrasive grain and a bond comprising ferric chloride, iron hydroxide and iron in an intimate mixture.

EDWARD VAN DER PYL. 

